MALARIA: Pyrethroid, DDT and malathion resistance

Pyrethroid, DDT and malathion resistance in the malaria vector Anopheles gambiae from the Democratic Republic of Congo

1. Jean Pierre Basilua Kanzaa,b,*, 
2. Elmostafa El Fahimec, 
3. Sanaa Alaouic,
4. El Mokhtar Essassib, 
5. Basil Brookee,f, 
6. André Nkebolo Malafua and
7. Francis Watsenga Tezzod

+Author Affiliations

1. ^aInstitut Supérieur des Techniques Médicales de Kinshasa (ISTM/KIN), Laboratoire Spécial d'Analyses Biomédicales, BP774 Kinshasa XI, Democratic Republic of Congo
2. ^bLaboratory of Heterocyclic Organic Chemistry URAC21, University Mohammed V-Agdal, Faculty of Sciences, Rabat, Morocco
3. ^cFunctional Genomics Platform-CNRST, Technical Support Unit for Scientific Research/UATRS, Rabat, Morocco
4. ^dNational Institute of Biomedical Research, Department of Parasitology, Department of Medical Entomology, Research Unit on Vectors of Malaria, Kinshasa, Democratic Republic of Congo
5. ^eCentre for Occupational, Tropical and Hospital Infections, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
6. ^fMalaria Entomology Research Unit, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

1. ↵*Corresponding author. E-mail: bkanzajp@yahoo.fr

• Received May 24, 2012.
• Revision received August 14, 2012.
• Accepted August 30, 2012.

Abstract

Background Malaria remains the most important parasitic disease in sub-Saharan Africa. We investigated the extent of resistance in the malaria vector Anopheles gambiae from the Democratic Republic of Congo (DRC) to three classes of insecticide approved by WHO for indoor residual spraying.

Method Standard WHO bioassays were performed on adult Anophelesmosquitoes reared in the laboratory from larvae collected from different sites. Molecular techniques were used for species identification and to identify knockdown resistance (kdr) and acetylcholinesterase (ace-1^R) mutations in individual mosquitoes.

Results Only A. gambiae s.s., the nominal member of the A. gambiaespecies complex, was found. Bioassays showed phenotypic resistance to the main insecticides used in the region, notably pyrethroids (deltamethrin, permethrin, lambda-cyhalothrin), an organochlorine (DDT) and an organophosphate (malathion). The L1014F kdr allele, often associated with resistance to pyrethroids and DDT, was detected in samples from all collection sites at varying frequencies. No ace-1^Rresistance alleles (associated with organophosphate and carbamate resistance) were detected.

Conclusions These data can be used to inform a resistance management strategy that requires comprehensive information concerning malaria vector species composition in the areas of interest, and their susceptibility to the insecticides proposed for their control.

http://trstmh.oxfordjournals.org/content/early/2012/10/19/trstmh.trs002.abstract